Latch installation tool



V March 17, 1970 A. E'. HAND ETAL l 3,500,884

LATCH INSTALLATION TOOL 4 Filed Nov. 20, 1967 3 Sheets-Sheet 1 March 17, 1970 A. E. HAND ETAI.

LATCH INSTALLATION TOOL Filed Nov. 20, 1967 5 Sheets-Sheet 2 March 17, 1970 A. E. HAND ETAL LATCH INSTALLATION TOOL 3 Sheets-Sheet 3 Filed Nov. 20, 196'? United States Patent O LATCH INSTALLATION TOOL Albert E. Hand, Southington, and Theodore H. Miller, New Britain, Conn., assignors to Emhart Corporation,

Bloomfield, Conn., a corporation of Connecticut Filed Nov. 20, 1967, Ser. No. 684,567 Int. Cl. B27c 9/00 U.S. Cl. 144-3 28 Claims ABSTRACT OF THE DISCLOSURE A latch installation tool having a frame including a pair of clamp plates is moved into clamping engagement with a door in orientation with a predetermined line of reference on the door by a pair of clamping elements which are pivotally supported on the frame and cammingly engage the plates. Various cutter assemblies supported in predetermined positions on the frame operably engage the door to form intersecting openings therein in orientation with the line of reference to receive various parts of a conventional latch or lock mechanism to be mounted on the door.

BACKGROUND OF INVENTION This invention relates in general to latch or lock installations tools and deals more particularly with a tool for installing a door latch of the so-called mortice type. To prepare a door to receive a latch of this type, a plurality of intersecting openings are formed therein. The vertical center line of the door outer edge, which is or may be beveled or inclined with respect to the side faces of the door, ordinarily provides a line of reference from which the centers of the various openings may be accurately located. A mortice opening through the door outer edge for receiving the latch case is usually centered on this line of reference. Backset dimensions normally provided by the latch manufacturer to aid in positioning various openings required to receive knob spindles, lock cylinders and like parts of a latch mechanism are also customarily measured from this reference line.

Accordingly, it is the general aim of the present invention to provide an improved latch installation tool for clampingly engaging a door in automatic alignment with a line of reference, such as aforedescribed, to facilitate the rapid and accurate formation of openings in the door required for the installation of a conventional latch or lock mechanism.

Other objects and advantages of the invention will be apparent from the following description and from the drawings forming a part thereof.

SUMMARY OF INVENTION In accordance with the present invention, a latch installation tool is provided having a frame including a pair of movable clamp plates for engaging opposite side faces of a door. Means are provided for positioning the frame in longitudinal alignment with the outer edge of the door and for camming the plates into clamping engagement with the door to further orient the frame relative to the vertical centerline of the door outer edge. Intersecting openings in the door accurately located and angularly positioned to receive associated parts of a conventional latch mechanism are formed by one of more cutter assemblies selectively positioned in predetermined locations on the frame.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a side elevation of a latch installation tool or jig embodying the present invention mounted on a 3,500,884 Patented Mar. 17, 1970 door and including a mortice cutter assembly for boring ne or more openings through the outer edge of the oor.

FIG. 2 is a front elevational of the tool of FIG. 1 but having the mortice cutter assembly removed therefrom and showing a boring cutter assembly supported thereon.

FIG. 3 is an end view of the tool of FIG. 1 and shows both the mortice and boring cutter assemblies illustrated in FIGS. 1 and 2.

FIG. 4 is a side elevation of the latch installation tool of FIG. 1 but shows a cutter assembly or router mounted thereon for forming an opening in the outer edge of the door.

FIG. 5 is a front elevation of the tool arranged as shown in FIG. 4, a portion of the frame and one clamp member being broken away.

FIG. 6` is a somewhat enlarged fragmentary sectional view taken generally along the line 6--6 of FIG. 4.

FIG. 7 is a somewhat enlarged fragmentary sectional View taken along the line 7-7 of FIG. 5.

FIG. 8 is a somewhat enlarged fragmentary rear elevation of the tool arranged as shown in FIG. 4.

FIG. 9 is a fragmentary sectional view taken along the line 9 9 of FIG. 5.

FIG. 10 is a fragmentary sectional view taken along the line 10-10 of FIG. 8.

FIG. 11 is a somewhat enlarged fragmentary sectional view taken along the line 11-11 of FIG. 7.

FIG. 12 is a somewhat enlarged fragmentary sectional view taken along the line 12-12 of FIG. 8.

FIG. 13 is a somewhat enlarged fragmentary sectional view taken along the line 13-13 of FIG. l.

FIG. 14 is a fragmentary sectional view taken along the line 14-14 of FIG. 13.

FIG. 15 is a somewhat enlarged sectional view taken along the line 15-15 of FIG. 2.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT Turning to the drawings, and first considering FIGS. 1-5, a latch installation tool or jig embodying the present invention and indicated generally at 10 is shown mounted on a hung door 12 having an upright stile including side faces 14, 14 and a forward or outer edge 16 beveled or inclined with respect to the side faces. The tool 10 comprises a frame indicated generally at 18 adapted for positioning in longitudinal alignment with the outer edge `and including a pair of movable clamp plates 20, 20. A pair of clamp members 22, 22 supported on the frame cammingly engage and move the plate 20, 20 equal distances toward each other and into clamping engagement with the side faces 14, 14 to further align the frame with the vertical centerline of the outer edge indicated at 24.

One or more cutter assemblies adapted for support in predetermined positions on the frame and movable in cutting engagement with the door form openings required for the installation of a mortice lock or latch mechanism (not shown). A mortice cutter assembly indicated generally at 26 in FIGS. l and 3 is adapted for support on the frame 18 in a longitudinal spaced series of positions to bore a single hole or a plurality of adjacent overlapping holes of desired depth through the door outer edge 16 to collectively form a mortice for receiving the case of the latch. Another cutter assembly 28 shown in FIGS. 2 and 3 is provided to bore an opening transversely through the door 12 for receiving a latch knob spindle, lock cylinder or the like. Still another cutter or router assembly 29 is shown in FIGS. 4 and 5 mounted on the frame for forming another opening in the door outer edge 16 surrounding the mortice to receive the face plate of the latch mechamsm.

To facilitate handling, the frame 18 and some of the other parts of the apparatus not subject to wear are preferably made from aluminum or other metal of relatively light weight. The frame 18 is laterally adjustable to ac commodate doors of varying thickness and has a central portion including a pair of substantially identical longitudinally spaced end blocks 30, 30 (FIG. 2) of somewhat lesser Width than the thickness of the narrowest door to be accommodated. Considering the lower end block 30 as it appears in FIGS. 7 and 8, it will be seen to include a substantially flat rearwardly facing surface 32 and has a recess formed at its inner end containing a bearing block 34. A parti-cylindrical recess 36 formed in the bearing block 34 opens rearwardly and inwardly, or toward the center of the frame. A pair of shafts 38 and 40 extend laterally through the block 30 and include end portions which project from opposite sides of the block. These shafts support the associated clamping device 22. The shaft 38 is secured against lateral movement relative to the block by a set screw 42. A stud 44 threaded at its outer or free end threadably engages the shaft 38 within the block 30, and projects radially outwardly therefrom.

Each shaft 40 is laterally adjustable relative to its associated supporting block 30 and to effect this adjustment a positioning driver generally indicated at 46 is provided. Referring to FIG. 7, the positioning driver 46 has a cylin- :lrical shank 48 extending into the block 30 in radial relationship with the shaft 40, and has an enlarged cylindri- :al base 50 bearing against a flattened surface portion of `:he latter shaft. An eccentric drive pin 52 projects from ;he base 50 and is received in a slot 54 which extends `:ransversely of the shaft 40. At its outer end the driver shank 48 is slotted to receive a tool for rotating the driver 16 to laterally adjust the position of the shaft 40 relative zo the block 30. A lock nut 56 threadably engages the )lock 30, surrounds the shank 48 and bears against the nase portion 50 to lock the shaft 40 in a desired position 3f lateral adjustment.

Leveling buttons 58, 58 are provided at each end of the frame 18 for longitudinally aligning it with the door 12 1nd for controlling the backset or distance from the longi- Ludinal centerline of the door outer edge to the center of :he opening formed by the cutter assembly 28. Each eveling button extends rearwardly from an associated )lock 30 and includes a crowned or parti-spherical end ortion 59. The leveling buttons engage the door outer :dge at longitudinally spaced points on the centerline Z4 to effect the desired condition of alignment. A plurality )f leveling button sets of various lengths are preferably )rovided for selective use to adapt the tool to the set- )ack requirements of a variety of latch mechanisms. For his reason each leveling button 58 is preferably releasably 'etained in its associated block 30 by an O-ring 60 shown n FIG. 11 engaging in a suitable groove in the button thank.

Each block 30 also carries a release member or slide 62 :'or disengaging the router assembly 29 from the frame 18 1s will be hereinafter further discussed. As best shown n FIGS. 7 and 8, each slide 62 is secured to the rear surface of an associated block 30 and has a longitudinally :Xtending slot 64 through which an associated leveling )utton 58 passes. Shoulder screws 66, 66 extend through he slot 64 and threadably engage the block 30 on oppotite sides of the leveling button to retain the slide for imited movement in a longitudinal direction. A ball deent mechanism in the block 30, and indicated generally tt 68 in FIG. l2 cooperates with ball receiving openings l0, 70 in the slide 62 to selectively retain the slide in its nactive or full line position and in its active or releasing )osition indicated by broken lines in FIG. 7. It should be loted that when the slide 62 is in the latter position, the nner end thereof extends inwardly through and beyond he recess 36.

The clamp plates 20, 20 are substantially identical but of opposite hand. Each such plate includes an inwardly facing clamping surface 72 for engaging an associated door side face 14 and a pair of longitudinally spaced and forwardly projecting ears 74, '74 (FIG. l) apertured to slidably receive the supporting shafts 38, 38 and 40, 40. Along the forward edge of each plate 20 there is formed a longitudinal spaced series of forwardly projecting teeth 76, 76 which are supported forwardly of the door outer edge 16 when the tool 10 is in clamping engagement with the door 12. The teeth may be integrally formed on the plates 20, 20, but preferably and as shown they are formed on a pair of durable metal inserts 78, 78 fastened in associated recesses in the forward edge of the plates and having opposing inwardly facing surfaces 79, 79 (FIG. 13). Each tooth 76 extends laterally inwardly for some distance beyond an associated surface 79 and includes a rearwardly facing surface 80 best shown in FIGS. 13 and 14.

Apertured bosses 82 and 84 on the outer surfaces of the plates 20, 20 are provided for supporting one or more cutter assemblies on the frame. The boss 82 (FIG. l) has a cylindrical hole 86 therethrough to accommodate the boring cutter assembly 28 and a somewhat smaller cylindrical hole '90 for receiving a locating pin associated with the latter cutter assembly. A pair of overlapping or interconnected cylindrical holes 92 and 94 also extend through the boss 82 to selectively accommodate another cutter assembly (not shown) similar to the assembly 28 but of somewhat smaller size in either of two positions for boring an opening to receive a spindle of a thumb turn on lock condition indicator. Additional holes are provided in the boss `84 to accommodate the tool 28 in still another position and to support a similar but somewhat smaller tool (not shown) in a still further boring position. To aid in vertically positioning the frame 18 on the door 12, horizontally opposed generally V-shaped notches 96, 96 are formed in the plate 20 in association with one or more of the aforedescribed holes. The notches provide indicia for positioning the frame 18 on the door in alignment with a horizontal reference line, such as 97, scribed on the door at a desired position above the lower edge thereof. Generally wedge shaped cam bosses 98, 98 (FIG. l) are integrally formed on each plate 20 and extend laterally outwardly from opposite ends thereof to cooperate with cams carried by the clamp devices 22 for moving the plates into clamping engagement with the door. Each cam 98 includes an arcuately shaped cam surface 100 which is inclined to the lateral direction and has its center of curvature on the axis of the shaft 40. The cam surfaces 100, 100 are preferably crowned or outwardly convex as best shown in FIG. l0.

Further considering the clamp members 22, 22, it will be noted that each such member is supported at an opposite end of the frame 18 for pivotal movement about the axis of an associated shaft 40 and is secured to the latter shaft in the manner illustrated in FIG. 2 for lateral adjustment therewith. Referring now particularly to the lower clamp member 22 as it appears in FIGIURES l-3, this member has a hollow body 102 overlying an associated part of the frame 18. A pair of legs 104, 104 extend from the body 102 in radial relation to the shaft 40 and on opposite sides of the frame. Each leg 104 carries a generally wedge shaped cam 106 (FIG. 8) for complementary engagement with an associated plate cam 98. Like the previously described cams 98, 98, each cam 106 includes an arcuately shaped cam surface 108 which has its center of curvature on the axis of the shaftv40. Each cam surface 108 is also convex or crowned to engage an associated cam surface 100 along an arcuate line of contact which has its center of curvature located at the clamping element pivot axis. Means for pivoting each clamp member 22 inwardly from a releasing position indicated by broken lines in FIG. l to a clamping position shown in full lines is provided by a knob 110 threaded onto an associated stud 44. The knob bears against a washer 112 (FIG. 7) which is contoured to exert a substantially uniform pressure on the clamp body 102 through the aforedescribed range of positions.

Tightening the knobs 110, 110 causes the clamp members 22, 22 to pivot toward their clamping positions so that the cams on the latter members and the plates 20, cooperate to move the plates equal distances toward each other. The positioning driver 46 is employed t0 center the leveling buttons 458, 58 between the cams 106, 106 so that the said buttons will be automatically longitudinally aligned with the door centerline 24 when the plates are brought into clamping engagement with the door. Due to the parti-spherical configuration of the button end portions 59, 59 the leveling buttons will rest on the centerline 24 although the door outer edge 16 may be beveled and therefore inclined with respect to the axes of the buttons.

Considering now the various cutter assemblies in the preferred order of use, and first referring to the mortise cutter assembly 26 shown in FIGS. 1, 3, 13 and 14, this cutter assembly is adapted for support on the frame forwardly of the door outer edge and includes a cutter or boring bit supported for rotation about a generally rearwardly extending axis and for axial movement into cutting engagement with the door. Means are provided for releasably retaining the cutter assembly 26 in a longitudinally spaced series of positions on the frame to bore a plurality of interconnected or overlapping holes of desired depth through the door outer edge 16 to collectively form a mortise for receiving the latch case.

The bit is indicated at 114 (FIGS. 1 and 13) and includes an elongated shank 116 adapted for connection at its forward end with a suitable power tool (not shown) for imparting rotation thereto. At the rear end of the shank there is formed a conventional spirally fluted cutting blade 117. An adjustable stop collar 118 surrounds the shank and is secured thereto by a set screw 119. Support for the bit 114 is provided by a support member 120 carrying a bearing Aor bushing 122 in which the shank 116 is journalled. The support member 120 is generally cylindrical and includes a fluted body portion 123 and a somewhat enlarged hollow base portion 124 having a rearwardly facing radially disposed bearing surface 126. A handle or locking lever 125 extends radially outwardly from the body portion. To release chips produced by the cutting operation a plurality of openings 127, 127 are formed in the base portion.

A locking cam 128 is threaded into the hollow base 124 for releasably retaining the cutter assembly 26 on the frame 18. The said cam includes a cylindrical portion 130 having a coaxially aligned cylindrical bore for receiving the cutter blade 117 in its retracted or inactive position as it appears in FIG. 13. Extending radially outwardly from the cylindrical portion 130 in axially spaced relation to the bearing surface 126 is a cam plate 134 (FIGS. 13 and 14) which includes substantially identical diametrically opposed end portions 136, 136. Each end portion 136 has a forwardly facing bearing surface 138 and also has a cam surface 140 which curves arcuately outwardly from the cylindrical portion 130 in a clockwise direction as viewed in FIG. 14. An annular bearing plate 142 surrounds the cylindrical portion 130 between the bearing surface 126 and the cam plate 134 and includes a forwardly opening annular recess containing an annular compression member 144. The compression member is preferably made from an elastomeric material and extends from the latter recess to engage the bearing surface 126. A rib 146 projects rearwardly from and preferably extends diametrically of the bearing plate 142.

The center assembly 26 is positioned on the frame 18 with the bearing plate 142 resting on the forwardly facing surfaces of associated teeth 78, 78 and the rib 146 extending transversely of the frame 18 and selectively positioned in the spaces between opposite pairs of adjacent teeth. A rearwardly directed force is applied to the body portion 123 to compress the elastomeric member 144 a suicient amount to permit the locking lever to be moved in a clockwise direction to bring the bearing surface 138 into engagement with associated teeth surfaces 80, 80. Further clockwise movement of the locking lever causes each cam surface to engage an associated insert surface 79 as best lshown in FIG. 14, thereby moving the cutter bit 114 to a centered position rbetween the plates 2l), 20l and into alignment with the reference line 12.4. The teeth 78, 78 are so spaced that the cutter assembly may be successfully positioned on the frame 18 to bore a series of overlapping or interconnected holes in the door which collectively form a generally rectangular mortise. Indicia or mortise longitudinal dimension is or may be indicated on the plates 20, 20 to provide a convenient reference for positioning the cutter assembly 26 to form a mortise of desired length. To control the depth of the mortise, the stop collar 118 is selectively positioned on the shank 116.

The router assembly 29 (FIGS. 4-6) is positioned on the frame after the mortise has been formed so that it is necessary to rout only a small area surrounding the mortise thereby minimizing the time required to perform this operation. Like the previously described cutter assembly, the router assembly 29 is also releasably retained on the frame 18 forward of the door outer edge and includes a support structure which carries a cutter or bit 147. The bit extends some distance into the ymortise and is arranged for rotation about a generally rearwardly extending axis for lateral and longitudinal movement relative to the frame 18.

Referring now to FIGS. 4-9, the router support structure includes a pair of stop blocks 148, 148 connected by a pair of parallel cylindrical rails or guide rods 150, 150. Each stop block has a substantially flat rearwardly facing surface 152 and a rearwardly and outwardly opening semi-cylindrical recess 154, as best shown in FIGS. 7 and 8. A generally semi-cylindrically shaped plunger 156 is received in each recess 154 and retained for longitudinal movement therein by a pair of plunger screws 158, 158, this for releasably retaining the router support structure on the frame. Each plunger is biased outwardly by a pair of compression springs 159, 159, each spring surrounding an associated screw 158. The outer end of each plunger has a conical outwardly converging surface 160 which is normally based to a position out of the recess 154.

The bit 147 is supported for longitudinal movement relative to the frame by a generally U-shaped guide block 164 (FIGS. 4, 5 and 6) which has a central portion 166 including a laterally extending slot 168 and a pair of rearwardly directed legs 170, 170 apertured to slidably receive the guide rods 150, 150. The oit 147 is further supported for rotary and lateral movement relative to the guide block 164 by a rectangular slide 172 (FIG. 6) which has a generally cylindrical central portion 174 projecting forwardly through the slot 168. Each end portion of the slide is received in a space between the guide block 164 and an associated guide rod 150. To support the slide for lateral movement relative to the guide block a pair of bearing members, 176, 176 slidably received on the guide rods between the guide block legs bear against the rear surface of the slide. A bushing 178 threadably received in the central portion 174 and retained in position therein by a lock nut 180 serves to journal the bit 147 for axial adjustment relative to the frame 18.

Referring particularly to FIG. 6, the bit 147 includes a shank 182 carrying a conventional router blade 184. A split collar 186 retains the bit in assembly with the bushing 178 which also serves as a thrust bearing. At its forward end the shank 182 is rounded and has radial grooves for receiving complementary ribs on a female adapter (not shown) for connecting the bit with a power source which may, for example, be a conventional rotary power tool. The adapter provides a quick release connection of somewhat universal type between the bit and its power source thereby eliminating the need for maintaining the power source in precise alignment with the bit during the cutting operation.

To adjust the lateral movement of the bit 147 and thereby control the lateral dimension of the router cut, a pair of gauge plates 188, 188 are secured to the forward surface of the guide block 164. Each gauge plate has an inwardly facing abutment surface 190 and is movable between positions of adjustment indicated by solid and broken lines in FIG. for positioning in the path of lateral movement of the bit 147 to limit the latter movement. In the illustrated embodiment the longitudinal movement of the bit is limited by the stop blocks 148, 148. However, additional stop means may be provided to limit this movement and thereby further control the longitudinal dimension of the router cut.

As the router assembly is moved into position on the frame 18 the plungers 158, 158 engage the rounded forward portions of the end blocks 30, 30 and are thereby urged into their respectively associated recesses 158, 158. When the stop blocks 148, 148 are aligned with the end blocks 30, 30 the springs 159, 159 urged the plungers into the recesses 36, 36 to retain the router assembly on the frame. Due to the semicylindrical configuration of each plunger and the complementary configuration of the recess 36 in which it is received the router assembly is thereby supported on the frame for limited pivotal movement about a longitudinal axis. Engagement of the conical surfaces 160, 160 with the end blocks 30, 30 urge the stop block surfaces 152, 152 into engagement with the beveled door outer edge 16 thereby causing the router assembly to pivot to a position wherein the bit 147 extends into the mortise and assumes an axially normal position with respect to the door outer edge as shown in FIG. 6. Thereafter, the power source is connected to the bit in the aforedescribed manner and the bit is moved longitudinally and laterally between its limits to accurately rout an opening surrounding the mortise.

As previously noted that tool 10 may be adapted to the setback requirements of a variety of latch mechanisms. To adapt the router assembly 29 to these requirements a plurality of sets of spacer pads (not shown) are provided. Each set of pads is used with a corresponding set of leveling buttons and comprises a pair of substantially identical rectangular blocks. Each pad is adapted to be secured to an associated stop block 148 adjacent its rear surface 152 to serve as a shim to compensate for increased spacing between the surfaces 152, 152 and the door outer edge 16 caused by changing the leveling buttons.

Removal of the router assembly 29 from the frame 18 is facilitated by moving the slides 62, 62 to their respective releasing positions in which positions they are retained by the spring ball detent mechanism 68, 68. In the releasing position the inner end of each slide 62 bears against an associated plunger 158 to hold the plunger in a retracted position so that the router assembly may be readily removed from the frame without first removing the frame from the door.

As previously noted the cutter assembly 28 is employed to form a transverse opening through the door communieating with the mortise for receiving a latch knob spindle or the like or to counterbore such an opening to receive a lock cylinder associated with the latch. 'Ihe cutter as- Sembly 28 includes a boring bit 194 journalled for rotation about laterally extending axis and axially movable into cutting engagement with the door. Referring particularly to FIG. l5 the boring cutter assembly is shown to comprise a hollow support member 196 which has a iluted gripping surface and supports a bushing 197 for journalling the bit 194. At its inner end the support member 196 has a radially disposed bearing surface 200 for engaging the boss 82. Projecting inwardly beyond the surface 200 is a generally cylindrical portion 202 adapted to be received in the opening 86 to align the cutter with the frame 18. A locating pin 204 adapted to be received in the hole 90 projects inwardly from the support member 196 beyond the cylindrical portion to further aid in positioning the cutter assembly 28 on the frame and to prevent rotation of the support member 196 as it is held in engagement with the frame during the cutting operation. The bit 194 has an elongated shank carrying a conventional boring cutter blade 206, shown in a retracted position in FIG. 15, and is adapted for connection with a power tool. A stop collar such as 208 (FIG. 2) may be employed to limit the axial movement of the bit and thereby control the depth of the cut when the cutter assembly 28 is used to perform a counter-boring operation.

The arrangement of the frame and the releasable arrangement of the various cutter assemblies with respect thereto provides a substantial advantage in that any of the cutter assemblies may be removed from the frame at any stage of the operation to permit insertion of the various lock parts into the openings formed without rst removing the frame from its clamped position on the door. Thus, as necessary, the cutter assembly may be adjusted and repositioned on the frame and the cutting operation resumed without risk of cutter misalignment.

The drawings show a preferred embodiment of the invention and such an embodiment has been described but it will be understood that various changes may be made from the construction disclosed and that the drawings and description are not to be construed as defining or limiting the scope of the invention the claims forming a part of the specification being relied upon for this purpose.

What is claimed is:

.1. A latch installation tool comprising a frame including a pair of clamp plates having opposing laterally spaced clamp faces for engaging opposite side faces of a door positioned between said plates, means supporting said plates for lateral movement toward and away from each other, means for positioning said frame in longitudinal alignment with the outer edge of said door, clamping means for moving said plates, said clamping means and each of said plates having engaging cam surfaces, at least one of said cam surfaces associated with each of said plates -being inclined to the lateral direction to cause said plates to move toward each other and into clamping engagement with said door side faces in response to movement of said clamping means in one direction, and a cutter assembly supported on said frame for operably engaging said door to form a latch part receiving opening therein.

2. A latch installation tool as set forth in claim 1 wherein said clamping means is supported on said frame for pivotal movement about a laterally extending axis.

3. A latch installation tool as set forth in claim 2 wherein said cam surfaces associated with each of said plates are engageable along arcuate lines of contact having centers of curvature on said pivot axis.

4. A latch installation tool as set forth in claim 2 including means for moving said clamping means in said one direction.

5. A latch installation tool as set forth in claim 4 wherein said means for moving said clamping means comprises a clamp knob supported by and threadably movable relative to said frame generally toward and away from said clamping means, said knob engaging said clamping means in radially spaced relation to said pivot axls.

6. A latch installation tool as set forth in claim 1 includng means for adjustably locating said clamping means relative to said positioning means to effect lateral alignment of the latter means with the central plane of said door when said clamp plates are brought into clamping engagement with said door.

7. A latch installation tool as set forth in claim 6 wherein said supporting means comprises a shaft extending laterally through said frame, said clamping means being carried by said shaft, and wherein said means for adjustably locating said clamping means comprises an eccentric mechanism associated with said frame and operably engaging said shaft for axially moving said shaft relative to said frame.

8. A latch installation tool as set forth in claim 1 wherein said frame includes a central portion intermediate said plates and forwardly of said door outer edge and wherein said positioning means comprises a pair of longitudinally spaced leveling buttons projecting rearwardly from said central portion for engaging said outer edge.

9. A latch installation tool as set forth in claim 8 including means for releasably retaining said leveling buttons in said central portion.

10. A latch installation tool as set forth in claim 8 wherein each of said leveling buttons has a parti-spherical end portion for engaging said outer edge.

11. A latch installation tool as set forth in claim 1 wherein said clamping means comprises a pair of longitudinally spaced clamp members, each of said members supported on said frame for pivotal movement about a laterally extending axis and including a pair of generally radially extending legs disposed on opposite sides of said frame, one of said engaging cam surfaces being associated with each of said legs.

12. A latch installation tool as set forth in claim 1 wherein said cutter assembly comprises a boring bit journalled for rotation about a laterally extending axis and axially movable relative to said frame.

13. A latch installation tool as set forth in claim 1 wherein said cutter assembly comprises a bit supported on said frame forwardly of said door outer edge for rotation about a generally rearwardly extending axis.

14. A latch installation tool as set forth in claim 13 wherein said bit is a routing cutter longitudinally and laterally movable relative to said frame.

15. A latch installation tool as set forth in claim 14 including means for axially adjusting said bit relative to said frame.

16. A latch installation tool as set forth in claim 13 including means for releasably retaining said -bit in a longitudinally spaced series of positions on said frame.

17. A latch installation tool as set forth in claim 16 wherein each of said plates includes a longitudinally spaced series of forwardly projecting teeth, said cutter assembly including a support member for jonrnalling said bit, and wherein said means for releasably retaining said bit comprises a laterally disposed rearwardly projecting rib carried by said support member for selective positioning between said teeth.

18. A latch installation tool as set forth in claim 16 wherein said means for releasably retaining said 'bit includes means for positioning said bit axis in the central plane of said door.

19. A latch 'installation tool as set forth in claim 18 wherein said plates include opposed longitudinally disposed surfaces and wherein said means for positioning said bit axis comprises a cam supported for pivotal movement on said bit axis and engageable with said opposed surfaces.

20. A latch installation tool for forming an opening in the outer edge of a door comprising a frame, positioning means for longitudinally aligning said frame with said outer edge, means for clamping said frame in engagement with the opposite side faces of said door, a cutter assembly including a rotary bit, means for supporting said bit on said frame for longitudinal and lateral movement relative to said outer edge in cutting engagement therewith, and means for releasably retaining said supporting means on said frame and for automatically positioning said bit axially normal to the plane of said outer edge when said supporting means is positioned on said frame.

21. A latch installation tool as set forth in claim 20 wherein said supporting means comprises a pair of laterally spaced longitudinally extending rails and a guide block mounted for longitudinal movement on said rails, said bit -being supported by `said guide block for rotation and lateral movement relative thereto.

22. A latch installation tool as set forth in claim 20 wherein said supporting means includes a pair of longitudinally spaced rearwardly facing bearing surfaces disposed in a plane axially normal to said bit and wherein said means for releasably retaining said supporting means comprises means for retaining said supporting means for pivotal movement about a longitudinal axis and for biasing said bearing surfaces into engagement with said outer edge.

23. A latch installation tool as set forth in claim 20 including means for moving said releasably retaining means to and retaining said means in a releasing position so that said cutter assembly may be removed from said frame while said frame is in clamping engagement with said door.

24. A latch installation tool as set forth in claim 20 including means for adjusting the lateral movement of said bit relative to said frame.

25. A latch installation tool comprising a frame including a pair of clamp plates having opposing laterally spaced clamp faces for engaging opposite side faces of a door positioned between said plates, means `supporting said plates for lateral movement toward and away from each other, means for positioning said frame in longitudinal alignment with the outer edge of said door, clamping means for moving said plates, said clamping means and each of said plates having coengaging cam surfaces for moving each of said plates toward the other and into clamping engagement with said door side faces in response to movement of said `clamping means in one direction, and means for supporting a cutter assembly on said frame for operably engaging said door to form a latch part receiving opening therein.

26. A latch installation tool as set forth in claim 25 wherein said clamping means is supported on said frame for pivotal movement about a laterally extending axis.

27. A latch installation tool as set forth in claim 25 including means for moving said clamping means in said one direction.

28. A latch installation tool as set `forth in claim 27 wherein said means for moving said clamping means comprises a clamp knob supported by and threadably movable relative to said frame generally toward and away from said clamping means, said knob engaging said clamping means in radially spaced relation to said pivot axis.

References Cited UNITED STATES PATENTS 971,627 10/ 1910 Nicholls 77-62 2,790,470 4/ 1957 Graham 144-3 3,327,573 6/ 1967 Prussiano 77-62 3,363,487 l/1968 Gohm 77-62 GERALD A. DOST, Primary Examiner '(gg UNITED STATES PATENT OFFICE CERTIEEICATE 0F CORRECTION Patent No. 3,500,884 Dated 'March 17. 1970 Invent0r(s) Albert E. Hand and Theodore H. Miller It is certified that error appears in theabov-id'entfied 'patentand that said Letters Patent are hereby corrected as shown below:

co1. 1, line 28, "installations" should read -installation Col. line 4, "elevational" should read -eleva1:ion

Col. line 42, following "Turning" insert now Col. line 10, "124" should read -24- line 11, "successfully" should read --successive1y Col. 4, line 30, preceding "spindle" insert '-knob' Col. 6,

SIGNED AND SEALED (SEAL) Attest:

Mouw inl-wn mmm. m. Mgmt! maliennot Patents 

